Featured Research

from universities, journals, and other organizations

Researchers make older beta cells act young again

Date:

October 12, 2011

Source:

Juvenile Diabetes Research Foundation International

Summary:

Researchers have identified a pathway responsible for the age-related decline of insulin-producing beta cells, and have shown that they can tweak it to get older beta cells to act young again -- and start dividing.

Share This

As a person ages, the ability of their beta cells to divide and make new beta cells declines. By the time children reach the age of 10 to 12 years, the ability of their insulin-producing cells to replicate greatly diminishes. If these cells, called beta cells, are destroyed -- as they are in type 1 diabetes -- treatment with the hormone insulin becomes essential to regulate blood glucose levels and get energy from food. Now, longtime JDRF-funded researchers at Stanford University have identified a pathway responsible for this age-related decline, and have shown that they can tweak it to get older beta cells to act young again -- and start dividing.

Related Articles

The work, which appears in the Oct. 12 issue of Nature, provides the most complete picture to date of the molecular and biochemical mechanisms that bring beta cell regeneration to a near halt as beta cells age. These findings may help pave a path for developing strategies to restore beta cell number to treat both type 1 and type 2 diabetes.

In their work, the researchers, led by Seung Kim, M.D., Ph.D., of Stanford University, found that a protein called PDGF, or platelet derived growth factor, and its receptor send beta cells signals to start dividing via an intricate pathway that controls the levels of two proteins in the beta cell nucleus, where cell division occurs. Working with young mice, Dr. Kim and his team found that PDGF binds to its receptor on the beta cell's surface and controls the level of these regulating proteins allowing cells to divide. However, in older mice, they discovered that beta cells lose PDGF receptors, and that this age-related change prevents beta cells from dividing. Dr. Kim and his colleagues further found that by artificially increasing the number of PDGF receptors, they can restore the ability of the beta cell to divide and generate new cells.

The researchers also show that this age-dependent beta cell proliferation pathway is also present in human beta cells. Similar to the findings with mice beta cells, the researchers found that juvenile human islet beta cells proliferate in response to PDGF, but adult human islet beta cells do not due to a reduced level of PDGF receptors.

In the past, researchers have used other techniques to trigger older beta cells to start dividing, but they have been met with challenging results, explains Dr. Kim, who is also a Howard Hughes Medical Institute investigator. "You can get these cells to grow but they will literally lose their specific identity as a beta cell," he says. "They will either stop making insulin, or they'll grow just fine but they will grow uncontrollably or into other cell types."

But with the advent of better genetic tools and the completion of the human genome project, that era has come to pass, he explains. "With these advanced technologies, we are now able to get a comprehensive view -- at the genetic level -- of the changes beta cells undergo as they age, and we can track these changes and study them in a systematic way," he adds. "By understanding what genes are turned on and off in a young beta cell, we can try to recreate that genetic environment in older beta cells such that they divide in a desirable, controlled manner."

By better understanding the mechanisms that control and govern pancreatic -cell proliferation, researchers could transform treatments for diabetes. The cascade leading from PDGF binding to its receptor on the beta cell's surface to changes in protein levels within the nucleus could inspire scientists with new ideas on how to discover new drugs to safely promote beta cell regeneration to replace those lost in diabetes.

"A major goal of JDRF's regeneration program is to find ways to preserve and restore functional beta cells as a cure for type 1 diabetes. One of the challenges is that adult beta cells do not readily replicate, and these new findings provide key insight on how the body regulates beta cell growth and replication," says Patricia Kilian, Ph.D., JDRF's scientific program director of regeneration research. "Based on these key scientific insights, we hope the new findings will help enable the discovery of safe therapies to promote beta cell regeneration."

More From ScienceDaily

More Health & Medicine News

Featured Research

Mar. 3, 2015 — Limp or firm, your handshake conveys subliminal social cues. Now, research reveals it also transmits chemical signals that could explain why the greeting evolved in the first ... full story

Mar. 3, 2015 — Loneliness brought about by the death of a spouse can trigger a wider network of depression-like symptoms, a study has found, but authors suggest that doctors are often too quick to attribute these ... full story

Mar. 3, 2015 — Family Based Interpersonal Psychotherapy (FB-IPT) is more effective in treating preadolescent children with depression compared to child-centered therapy (CCT), a recent study has found. ... full story

Mar. 3, 2015 — Two of the four known groups of human AIDS viruses (HIV-1 groups O and P) have originated in western lowland gorillas, according to new research. The scientists conducted a comprehensive survey of ... full story

Mar. 3, 2015 — Scientists have succeeded in producing cartilage formed from embryonic stem cells that could in future be used to treat the painful joint condition osteoarthritis. With their huge capacity to ... full story

Mar. 3, 2015 — Everyone worries about losing their memory as they grow older—memory loss remains one of the most common complaints of the elderly. But the molecular reasons behind the processes remain unclear, ... full story

Mar. 3, 2015 — A strong link has been made between subthreshold manic episodes and likelihood of developing bipolar disorder in children of parents with bipolar disorder. The study’s findings could improve ... full story

Mar. 2, 2015 — Despite sharp increases in spending on cancer treatment, cancer mortality rates in the United States have decreased only modestly since 1970, a study has found. "Our results suggest that cancer care ... full story

Mar. 2, 2015 — In the first study of its kind since the 1920s, rats in New York City were found to carry a flea species capable of transmitting plague pathogens. Among them: 500-plus Oriental rat fleas, notorious ... full story

Mar. 2, 2015 — A newly published study is the first to report an association between bisphenol-A (BPA), a common plasticizer used in a variety of consumer food and beverage containers, with autism spectrum disorder ... full story

Featured Videos

Mom Triumphs Over Tragedy, Helps Other Families

AP (Mar. 3, 2015) — After her son, Dax, died from a rare form of leukemia, Julie Locke decided to give back to the doctors at St. Jude Children&apos;s Research Hospital who tried to save his life. She raised $1.6M to help other patients and their families. (March 3)
Video provided by AP

Woman Convicted of Poisoning Son

AP (Mar. 3, 2015) — A woman who blogged for years about her son&apos;s constant health woes was convicted Monday of poisoning him to death by force-feeding heavy concentrations of sodium through his stomach tube. (March 3)
Video provided by AP

More Coverage

Oct. 12, 2011 — Researchers have identified a key molecular pathway responsible for the natural decrease in the proliferation of insulin-producing cells that occurs as a person ages. Artificially activating this ... read more

Related Stories

Sep. 17, 2014 — Aging of insulin-secreting cells is coupled to a progressive decline in signal transduction and insulin release, according to a recent study. Aging is among the largest known risk factors for many ... full story

July 31, 2014 — Researchers discover a simple peptide that can induce new beta-cell formation in the pancreas. The findings show promise for a new approach to treating type 1 diabetes. "We have found a ... full story

June 19, 2014 — A gene mutation sets off an accumulation of unhealthy beta cells that can no longer produce insulin needed to control blood sugar, says a researcher who lives with type 1 diabetes himself. The loss ... full story

Mar. 19, 2014 — A cellular pathway that is responsible for keeping blood sugar levels low, has been found, and may prevent the onset of type 2 diabetes. Following a meal, beta cells found in islets of the pancreas ... full story

Oct. 29, 2013 — The pancreas is a large organ that wraps around our gut, and produces the exact amount of insulin our bodies need when we eat -- except when we start to develop diabetes, and insulin production slows ... full story

ScienceDaily features breaking news and videos about the latest discoveries in health, technology, the environment, and more -- from major news services and leading universities, scientific journals, and research organizations.